Build Material And Applications Thereof

ABSTRACT

In one aspect, build materials operable for use in 3D printing systems are described herein. In some embodiments, a build material comprises about 10 to 30 percent by weight of an oligomeric curable material; about 50 to 75 percent by weight of at least one diluent; and about 3 to 15 percent by weight of a reactive component. Moreover, in some cases, the build material is free or substantially free of a non-reactive wax component.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part application of U.S. patentapplication Ser. No. 13/043,876, filed on Mar. 9, 2011.

FIELD OF THE INVENTION

The present invention relates to build materials for three dimensional(3D) printing systems.

BACKGROUND OF THE INVENTION

Commercially available three dimensional printers, such as the Projet™3D Printers manufactured by 3D Systems of Rock Hill, S.C., use a buildmaterial or ink that is jetted through a print head as a liquid to formvarious thermopolymer parts. Other three dimensional printing systemsalso use a build material that is jetted through a print head. In someinstances, the build material is solid at ambient temperatures andconverts to liquid at elevated jetting temperatures. In other instances,the build material is liquid at ambient temperatures.

SUMMARY OF THE INVENTION

In one aspect, build materials operable for use in 3D printing systemsare described herein which, in some embodiments, may offer one or moreadvantages over prior build materials. In some embodiments, for example,a build material described herein exhibits high stiffness, therebyproviding finished parts that are useful in various engineeringapplications.

A build material described herein, in some embodiments, comprises about10 to 30 percent by weight of an oligomeric curable material; about 50to 75 percent by weight of at least one diluent; and about 3 to 15percent by weight of a reactive component. Moreover, in some cases, thebuild material is free or substantially free of a non-reactive waxcomponent. In some embodiments, for example, a build material describedherein comprises less than about 5 percent by weight, less than about 1percent by weight, or less than about 0.5 percent by weight of anon-reactive wax component. Further, in some cases, the reactivecomponent of a build material described herein comprises an isocyanurate(meth)acrylate. Additionally, in some embodiments, a build materialdescribed herein can further comprise one or more additives selectedfrom the group consisting of photoinitiators, inhibitors, stabilizingagents, sensitizers, and combinations thereof.

Moreover, a build material described herein, in some embodiments, canexhibit one or more desired mechanical and/or thermal properties whencured. For example, in some cases, a build material when cured exhibitsone or more of a tensile modulus greater than about 2200 MPa, a tensilestrength greater than about 45 MPa, and a break elongation of about5-20%, when measured according to ASTM D 638. Further, in someinstances, a build material described herein when cured exhibits a heatdeflection temperature ranging from about 45° C. to about 100° C. whentested according to ASTM D 648.

In another aspect, compositions comprising three dimensionally printedarticles or objects are described herein. In some embodiments, acomposition comprises a three dimensionally printed article comprising abuild material described herein, such as a build material comprisingabout 10 to 30 percent by weight of an oligomeric curable material;about 50 to 75 percent by weight of at least one diluent; and about 3 to15 percent by weight of a reactive component. The reactive component, insome instances, comprises an isocyanurate (meth)acrylate. Moreover, insome cases, the build material is free or substantially free of anon-reactive wax component.

In another aspect, methods of printing a three dimensional article orobject are described herein. In some embodiments, a method of printing athree dimensional article comprises selectively depositing layers of afluid build material to form the three dimensional article on asubstrate, the build material comprising a build material describedherein. In some cases, for example, the build material comprises about10 to 30 percent by weight of an oligomeric curable material; about 50to 75 percent by weight of at least one diluent; and about 3 to 15percent by weight of a reactive component. Further, the reactivecomponent, in some instances, comprises an isocyanurate (meth)acrylate.Moreover, in some embodiments, the build material is free orsubstantially free of a non-reactive wax component. Additionally, insome instances, a method of printing a three dimensional article furthercomprises supporting at least one layer of the build material with asupport material. Moreover, the build material and/or support material,in some embodiments, can be selectively deposited according to an imageof the three dimensional article, the image being in a computer readableformat such as a CAD format. In addition, in some cases, a method ofprinting a three dimensional article described herein further comprisescuring the build material.

These and other embodiments are described in greater detail in thedetailed description which follows.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments described herein can be understood more readily by referenceto the following detailed description and examples and their previousand following descriptions. Elements, apparatus and methods describedherein, however, are not limited to the specific embodiments presentedin the detailed description and examples. It should be recognized thatthese embodiments are merely illustrative of the principles of thepresent invention. Numerous modifications and adaptations will bereadily apparent to those of skill in the art without departing from thespirit and scope of the invention.

In addition, all ranges disclosed herein are to be understood toencompass any and all subranges subsumed therein. For example, a statedrange of “1.0 to 10.0” should be considered to include any and allsubranges beginning with a minimum value of 1.0 or more and ending witha maximum value of 10.0 or less, e.g., 1.0 to 5.3, or 4.7 to 10.0, or3.6 to 7.9.

All ranges disclosed herein are also to be considered to include the endpoints of the range, unless expressly stated otherwise. For example, arange of “between 5 and 10” should generally be considered to includethe end points 5 and 10.

Further, when the phrase “up to” is used in connection with an amount orquantity, it is to be understood that the amount is at least adetectable amount or quantity. For example, a material present in anamount “up to” a specified amount can be present from a detectableamount and up to and including the specified amount.

The terms “three dimensional printing system,” “three dimensionalprinter,” “printing,” and the like generally describe various solidfreeform fabrication techniques for making three dimensional objects byselective deposition, jetting, fused deposition modeling, and othertechniques now known in the art or that may be known in the future thatuse a build material to fabricate the three dimensional object.

In one aspect, build materials operable for use in 3D printing systemsare described herein. A build material described herein can be fluid atjetting temperatures encountered in 3D printing systems. In someembodiments, a build material solidifies by freezing once deposited on asurface during the fabrication of a three dimensionally printed articleor object. In other embodiments, a build material remains substantiallyfluid upon deposition on a surface during the fabrication of a threedimensionally printed article or object.

In some embodiments, a build material described herein comprises anoligomeric curable material, at least one diluent, and a reactivecomponent, wherein the reactive component comprises at least onechemical moiety that is polymerizable with a chemical moiety containedin the oligomeric curable material and/or the at least one diluent.Additionally, in some cases, a build material further comprises anon-reactive component that does not comprise a chemical moiety that ispolymerizable with a chemical moiety contained in the oligomeric curablematerial or the at least one diluent. Alternatively, in other instances,a build material is free or substantially free of a non-reactivecomponent. A build material that is “substantially free” of anon-reactive component can comprises less than about 5 weight percent,less than about 3 weight percent, less than about 1 weight percent, orless than about 0.5 weight percent non-reactive component, based on thetotal weight of the build material. Moreover, in some embodiments, abuild material described herein further comprises one or more additivesselected from the group consisting of photoinitiators, inhibitors,stabilizing agents, sensitizers, and combinations thereof.

Turning now to specific components of build materials, build materialsdescribed herein comprise an oligomeric curable material. Any oligomericcurable material not inconsistent with the objectives of the presentinvention can be used. In some embodiments, an oligomeric curablematerial comprises one or more curable chemical species. In someembodiments, an oligomeric curable material comprises one or morephoto-curable chemical species. In some embodiments, an oligomericcurable material comprises one or more UV-curable chemical species. Insome embodiments, an oligomeric curable material is photo-curable atwavelengths ranging from about 300 nm to about 400 nm. Alternatively, insome embodiments, an oligomeric curable material is photo-curable atvisible wavelengths of the electromagnetic spectrum, such as wavelengthsfrom about 400 nm to about 700 nm.

In some embodiments, an oligomeric curable material described hereincomprises one or more species of (meth)acrylates. As used herein, theterm “(meth)acrylate” includes acrylate or methacrylate or mixtures orcombinations thereof. In some embodiments, an oligomeric curablematerial comprises urethane (meth)acrylate resins. In some embodiments,UV curable urethane (meth)acrylate resins can comprise any methacrylateor acrylate resin which polymerizes in the presence of a free radicalphotoinitiator, is thermally stable in an exposed state for at least oneweek at the jetting temperature and for at least 4 weeks in an enclosedstate, and/or has a boiling point greater than the jetting temperature.In some embodiments, an oligomeric curable material has a flash pointabove the jetting temperature.

Urethane (meth)acrylates suitable for use in build materials describedherein can be prepared in a known manner, typically by reacting ahydroxyl-terminated oligomeric urethane with acrylic acid or methacrylicacid to give the corresponding urethane (meth)acrylate, or by reactingan isocyanate-terminated prepolymer with hydroxyalkyl acrylates ormethacrylates to give the urethane (meth)acrylate. Suitable processesare disclosed, inter alia, in EP-A 114 982 and EP-A 133 908. The weightaverage molecular weight of such (meth)acrylate oligomers is generallyin the range from about 400 to 10,000, or from about 500 to 7,000.Urethane (meth)acrylates are also commercially available from theSARTOMER Company under the product names CN980, CN981, CN975 and CN2901,or from Bomar Specialties Co. (Winsted, Conn.) under the product namesBR-571 and BR-741. In some embodiments described herein, a urethane(meth)acrylate oligomer has a viscosity ranging from about 140,000centipoise (cP) to about 160,000 cP at about 50° C. In some embodimentsdescribed herein, a urethane (meth)acrylate oligomer has a viscosityranging from about 125,000 cP to about 175,000 cP at about 50° C. Insome embodiments described herein, a urethane (meth)acrylate oligomerhas a viscosity ranging from about 100,000 cP to about 200,000 cP atabout 50° C. In some embodiments described herein, a urethane(meth)acrylate oligomer has a viscosity ranging from about 10,000 cP toabout 300,000 cP at about 50° C.

An oligomeric curable material can be present in a build materialdescribed herein in any amount not inconsistent with the objectives ofthe present invention. In some embodiments, an oligomeric curablematerial is present in the build material composition in an amountranging from about 10 weight percent to about 50 weight percent, basedon the total weight of the build material. An oligomeric curablematerial, in some embodiments, is present in the build material in anamount ranging from about 10 weight percent to about 40 weight percent,about 10 weight percent to about 30 weight percent, about 15 weightpercent to about 50 weight percent, about 15 weight percent to about 40weight percent, about 15 weight percent to about 30 weight percent,about 15 weight percent to about 25 weight percent, about 20 weightpercent to about 50 weight percent, about 20 weight percent to about 40weight percent, about 20 weight percent to about 30 weight percent,about 30 weight percent to about 60 weight percent, about 30 weightpercent to about 50 weight percent, about 35 weight percent to about 45weight percent, about 40 weight percent to about 60 weight percent, orabout 40 weight percent to about 50 weight percent, based on the totalweight of the build material.

In some embodiments described herein, the oligomeric curable materialand the reactive component each contain one or more functional groups orchemical moieties that can react with one another, for example in apolymerization reaction. In some embodiments, the oligomeric curablematerial and the reactive component are capable of reacting with oneanother through free radical polymerization. In some embodiments, theoligomeric curable material and the reactive component are capable ofreacting with one another through polymerization between points ofunsaturation. In some embodiments, the oligomeric curable material andthe reactive component are capable of reacting with one another throughpolymerization of ethyleneically unsaturated moieties. In someembodiments, the oligomeric curable material and the reactive componentcan each contain one or more reactive functional groups comprising thesame chemical moiety. In other embodiments, the oligomeric curablematerial and the reactive component can each contain one or morereactive functional groups comprising different chemical moieties. Insome embodiments, a build material described herein comprises anoligomeric curable material, a reactive component, and at least onediluent, wherein the oligomeric curable material and the reactivecomponent each contain one or more acrylate or methacrylate moieties. Insome embodiments, the oligomeric curable material and the reactivecomponent each contain one or more vinyl moieties. In some embodiments,the oligomeric curable material and the reactive component each containone or more vinyl ether moieties.

Build materials described herein also comprise a reactive component. Anyreactive component not inconsistent with the objectives of the presentinvention may be used. In some embodiments, the reactive component issolid. For example, in some embodiments, a build material describedherein comprises a reactive component that is solid at about 25° C. Insome embodiments, the reactive component is solid at about 30° C., atabout 40° C., or at about 50° C. In some embodiments, the reactivecomponent is solid at about 75° C. In some embodiments, the reactivecomponent is solid at standard temperature and pressure (STP)conditions.

In addition, in some embodiments, the reactive component is crystallineor substantially crystalline. In some embodiments, the reactivecomponent is crystalline or substantially crystalline at one or moretemperatures recited herein. For example, in some embodiments, thereactive component is crystalline or substantially crystalline at about25° C., at about 30° C., at about 40° C., at about 50° C., or at about75° C. In some embodiments, the reactive component is crystalline orsubstantially crystalline at standard temperature and pressureconditions.

Moreover, in some embodiments, a reactive component described hereinremains solid or crystalline or substantially crystalline when combinedwith other components to form a build material. In some cases, a solid,crystalline, or substantially crystalline reactive component describedherein is phase separated in the build material. For example, in someembodiments, the reactive component is present in the build material ascrystalline or substantially crystalline regions within an otherwisefluid build material. In some embodiments, the reactive component may bepresent in the build material as crystalline or substantiallycrystalline particles. In some embodiments, the particles are about 1 toabout 100 μm in diameter. In some embodiments, the particles are about 1to about 50 μm in diameter, about 1 to about 30 μm in diameter, about 1to about 10 μm in diameter, about 500 to about 1000 nm in diameter, orabout 100 to about 500 nm in diameter. Therefore, in some embodiments, abuild material described herein comprises an oligomeric curablematerial, a reactive component, and at least one diluent, wherein thereactive component comprises at least one chemical moiety that ispolymerizable with a chemical moiety contained in the oligomeric curablematerial and/or the at least one diluent, and wherein the reactivecomponent is solid and/or crystalline or substantially crystalline whencombined with the other components of the build material.

Alternatively, in other embodiments, a reactive component describedherein does not necessarily remain solid, crystalline, or substantiallycrystalline when combined with other components to form a buildmaterial. Instead, in some embodiments, the reactive component dissolvesor substantially dissolves when combined with other components to form abuild material described herein. Thus, in some cases, a reactivecomponent described herein is not phase separated in the build materialbut instead is homogeneously distributed or dispersed throughout thebuild material. Moreover, in some embodiments, a build materialdescribed herein is a single-phase build material at any giventemperature between about 25° C. and about 75° C.

As described herein, in some embodiments, the reactive componentcomprises one chemical moiety that is polymerizable with a chemicalmoiety contained in the oligomeric curable material and/or the at leastone diluent. In some embodiments, the reactive component comprises morethan one chemical moiety that is polymerizable with a chemical moietycontained in the oligomeric curable material and/or the at least onediluent. In some embodiments, the reactive component comprises twochemical moieties that are polymerizable with a chemical moietycontained in the oligomeric curable material and/or the at least onediluent. In some embodiments, the reactive component comprises threechemical moieties that are polymerizable with a chemical moietycontained in the oligomeric curable material and/or the at least onediluent. In some embodiments, the reactive component comprises more thanthree chemical moieties that are polymerizable with a chemical moietycontained in the oligomeric curable material and/or the at least onediluent.

In some embodiments, a monofunctional reactive component of a buildmaterial described herein comprises only one chemical moiety that ispolymerizable with a chemical moiety contained in the oligomeric curablematerial or the at least one diluent in a certain way, for examplethrough a polymerization reaction between ethyleneically unsaturatedmoieties. Non-limiting examples of monofunctional reactive componentssuitable for use in some embodiments described herein include chemicalspecies that contain only one (meth)acrylate group, only oneethyleneically unsaturated group, or only one vinyl group.

In some embodiments, a polyfunctional reactive component of a buildmaterial described herein comprises more than one chemical moiety thatcan react with a chemical moiety contained in the oligomeric curablematerial or the at least one diluent. In some embodiments, apolyfunctional reactive component of a build material described hereincomprises more than one chemical moiety that can react with a chemicalmoiety contained in the oligomeric curable material or the at least onediluent through a polymerization reaction between ethyleneicallyunsaturated moieties.

In some embodiments, a difunctional reactive component comprises twochemical moieties that can react with chemical moieties contained in anoligomeric curable material. In some embodiments, a difunctionalreactive component comprises two chemical moieties that can react withchemical moieties contained in an oligomeric curable material through apolymerization reaction between ethyleneically unsaturated moieties.Non-limiting examples of difunctional reactive components suitable foruse in some embodiments described herein include chemical species thatcontain two (meth)acrylate groups, two ethyleneically unsaturatedgroups, or two vinyl groups.

In some embodiments, a trifunctional reactive component comprises threechemical moieties that can react with chemical moieties contained in anoligomeric curable material. In some embodiments, a trifunctionalreactive component comprises three chemical moieties that can react withchemical moieties contained in an oligomeric curable material through apolymerization reaction between ethyleneically unsaturated moieties.Non-limiting examples of trifunctional reactive components suitable foruse in some embodiments described herein include chemical species thatcontain three (meth)acrylate groups, three ethyleneically unsaturatedgroups, or three vinyl groups.

In some embodiments described herein, the reactive component of a buildmaterial described herein comprises at least one of the following: anon-oligomeric urethane (meth)acrylate, a urea (meth)acrylate, and anisocyanurate (meth)acrylate. A non-limiting example of a non-oligomericurethane (meth)acrylate useful in some embodiments is2-methacryloxyethyl phenyl urethane, which is commercially availablefrom Hampford Research, Inc., under the trade name 2-MEP. In someembodiments, the reactive component is selected from the groupconsisting of (i) an isocyanurate tri(meth)acrylate; (ii) a speciesdefined by the formula R¹—NHCOO—R²—R³, wherein R¹ is C_(n)H_((2n+2))(wherein n=4-36), R² is C_(n)H_((2n+2)) (wherein n=2-36), and R³ is—OCOCH═CH₂ or —OCOC(CH₃)═CH₂; (iii) a species defined by the formulaR¹—R²—NHCOO—R³—OOC—NH—R²—R¹, wherein R¹ is —OCOCH═CH₂ or —OCOC(CH₃)═CH₂,R² is C_(n)H_((2n+2)) (wherein n=2-36), and R³ is C_(n)H_((2n+2))(wherein n=2-36); (iv) a species defined by the formula R¹—NHCONH—R²—R³,wherein R¹ is C_(n)H_((2n+2)) (wherein n=4-36), R² is C_(n)H_((2n+2))(wherein n=2-36), and R³ is —OCOCH═CH₂ or —OCOC(CH₃)═CH₂; and (v) aspecies defined by the formula R¹—R²—NHCONH—R³—OOC—NH—R²—R¹, wherein R¹is —OCOCH═CH₂ or —OCOC(CH₃)═CH₂, R² is C_(n)H_((2n+2)) (wherein n=2-36),and R³ is C_(n)H_((2n+2)) (wherein n=2-36).

In some embodiments, the reactive component comprises anitrogen-containing ring. In other embodiments, the reactive componentis an isocyanurate. In some embodiments, the reactive component is anisocyanurate tri(meth)acrylate. In some embodiments, the reactivecomponent comprises tris(2-hydroxy ethyl)isocyanurate triacrylate.Non-limiting examples of an isocyanurate triacrylate useful in someembodiments described herein include the species commercially availablefrom the SARTOMER Company under the trade name SR 368 and from HampfordResearch, Inc., under the trade name THEIC.

The amount of a reactive component in a build material described hereincan be selected according to one or a variety of factors, including thejetting temperatures of the 3D printing system, the desired viscosity ofthe build material, the required mechanical integrity of the buildmaterial for printing applications, the desired deposition rates of thebuild material and any support material used, the desired breakelongation of the cured build material, the desired tensile modulus ofthe cured build material, the desired tensile strength of the curedbuild material, and the desired resistance to distortion of the curedbuild material. In some embodiments, a reactive component as describedherein comprises about 3 to about 50 percent by weight of a buildmaterial described herein. In some embodiments, a reactive componentcomprises about 3 to about 40 weight percent, about 3 to about 30 weightpercent, about 3 to about 25 weight percent, about 3 to about 20 weightpercent, about 3 to about 15 weight percent, about 3 to about 10 weightpercent, about 5 to about 50 weight percent, about 5 to about 30 weightpercent, about 5 to about 25 weight percent, about 5 to about 20 weightpercent, about 5 to about 15 weight percent, about 5 to about 10 weightpercent, about 10 to about 40 weight percent, about 10 to about 20weight percent, or about 10 to about 15 weight percent of a buildmaterial described herein, based on the total weight of the buildmaterial.

In some embodiments described herein, a reactive component exhibits asharp melting point. In some embodiments, a reactive component meltsover a narrow range of temperatures. In some embodiments, a reactivecomponent melts over a temperature range of about 1° C. to about 10° C.In some embodiments, a reactive component melts over a temperature rangeof about 1° C. to about 8° C. In some embodiments, a reactive componentmelts over a temperature range of about 1° C. to about 5° C. In someembodiments, a reactive component having a sharp melting point meltsover a temperature range of X±2.5° C., where X is the temperature atwhich the freezing point is centered (e.g., X=53° C.). In someembodiments described herein, a build material comprises an oligomericcurable material, a reactive component, and at least one diluent,wherein the reactive component comprises at least one chemical moietythat is polymerizable with a chemical moiety contained in the oligomericcurable material and/or the at least one diluent, and wherein thereactive component exhibits a melting point range of about 1° C. toabout 10° C.

Additionally, in some embodiments, a reactive component of a buildmaterial described herein has a melting point over a broad range oftemperatures applicable to 3D printing systems. Reactive componentsuseful in some embodiments described herein can exhibit melting pointranges centered at any temperatures not incompatible with the objectivesof the present invention. In some embodiments, a reactive componentexhibits a melting point range centered between about 40° C. and about100° C. In some embodiments, a reactive component exhibits a meltingpoint range centered between about 40° C. and about 50° C., betweenabout 51° C. and about 65° C., between about 66° C. and about 80° C., orbetween about 81° C. and about 100° C.

Build materials described herein also comprise at least one diluent. Anydiluent not inconsistent with the objectives of the present inventioncan be used. One or more diluents, in some embodiments, are added to thebuild material to control viscosity, but can also improve other physicalproperties of the material, including by improving adhesion of the curedcomposition to the build platform.

In some embodiments, at least one diluent of a build material describedherein comprises one or more chemical moieties that can react with achemical moiety contained in the oligomeric curable material and/or thereactive component. In some embodiments, at least one diluent comprisesone or more chemical moieties that can react with a chemical moietycontained in the oligomeric curable material and/or the reactivecomponent in a certain way, for example through a polymerizationreaction between ethyleneically unsaturated moieties.

In some embodiments, a diluent of a build material described hereincontains one or more (meth)acrylate moieties. Any (meth)acrylic diluentnot inconsistent with the objectives of the present invention can beused. In some embodiments, a (meth)acrylic diluent has a viscosity lessthan about 13 centipoise. Moreover, in some embodiments, a (meth)acrylicdiluent is monofunctional or polyfunctional.

For low molecular weight materials, methacrylates, dimethacrylates,triacrylates, and diacrylates can be used in a variety of combinationsas diluents. These include tetrahydrofurfuryl methacrylate, triethyleneglycol dimethacrylate, 2-phenoxyethyl methacrylate, lauryl methacrylate,ethoxylated trimethylolpropane triacrylate, polypropylene glycolmonomethacrylate, polyethylene glycol monomethacrylate, cyclohexanedimethanol diacrylate, and tridecyl methacrylate.

In some embodiments, a (meth)acrylic diluent comprises diacrylate and/ordimethacrylate esters of aliphatic, cycloaliphatic or aromatic diols,including 1,3- or 1,4-butanediol, neopentyl glycol, 1,6-hexanediol,diethylene glycol, triethylene glycol, tetraethylene glycol,polyethylene glycol, tripropylene glycol, ethoxylated or propoxylatedneopentyl glycol, 1,4-dihydroxymethylcyclohexane,2,2-bis(4-hydroxycyclohexyl)propane or bis(4-hydroxycyclohexyl)methane,hydroquinone, 4,4′-dihydroxybiphenyl, bisphenol A, bisphenol F,bisphenol S, ethoxylated or propoxylated bisphenol A, ethoxylated orpropoxylated bisphenol F or ethoxylated or propoxylated bisphenol S.

A (meth)acrylic diluent, in some embodiments, comprises one or moretri(meth)acrylates. In some embodiments, tri(meth)acrylates comprise1,1-trimethylolpropane triacrylate or methacrylate, ethoxylated orpropoxylated 1,1,1-trimethylolpropanetriacrylate or methacrylate,ethoxylated or propoxylated glycerol triacrylate, pentaerythritolmonohydroxy triacrylate or methacrylate.

In some embodiments, a (meth)acrylic diluent of a build materialdescribed herein comprises one or more higher functional acrylates ormethacrylates such as dipentaerythritol monohydroxy pentaacrylate orbis(trimethylolpropane) tetraacrylate. In some embodiments, a(meth)acrylate diluent has a molecular weight ranging from about 250 to700.

In some embodiments, a diluent is selected from the group consisting ofallyl acrylate, allyl methacrylate, methyl (meth)acrylate, ethyl(meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate,isobutyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl(meth)acrylate, n-octyl (meth)acrylate, n-decyl (meth)acrylate andn-dodecyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2- and3-hydroxypropyl (meth)acrylate, 2-methoxyethyl(meth)acrylate,2-ethoxyethyl (meth)acrylate and 2- or 3-ethoxypropyl (meth)acrylate,tetrahydrofurfuryl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl acrylate,cyclohexyl methacrylate, 2-phenoxyethyl acrylate, glycidyl acrylate andisodecyl acrylate.

Non-limiting examples of diluents useful in some embodiments describedherein include the following: isobornyl acrylate (IBOA), commerciallyavailable from SARTOMER under the trade name SR 506 or SR 506A;isobornyl methacrylate, commercially available from SARTOMER under thetrade name SR 423A; triethylene glycol diacrylate, commerciallyavailable from SARTOMER under the trade name SR 272; triethylene glycoldimethacrylate, commercially available from SARTOMER under the tradename SR 205; an alkoxylated tetrahydrofurfuryl acrylate, commerciallyavailable from SARTOMER under the trade name SR 611; and amonofunctional urethane acrylate, commercially available from RAHN underthe trade name GENOMER 1122.

A diluent such as a (meth)acrylic diluent can be present in a buildmaterial in any amount not inconsistent with the objectives of thepresent invention. In some embodiments, a build material comprises about10 weight percent to about 80 weight percent, about 10 weight percent toabout 75 weight percent, about 10 weight percent to about 70 weightpercent, about 30 weight percent to about 80 weight percent, about 30weight percent to about 75 weight percent, about 30 weight percent toabout 70 weight percent, about 40 weight percent to about 80 weightpercent, about 40 weight percent to about 75 weight percent, about 40weight percent to about 70 weight percent, about 50 weight percent toabout 80 weight percent, about 50 weight percent to about 75 weightpercent, about 50 weight percent to about 70 weight percent, about 60weight percent to about 80 weight percent, about 60 weight percent toabout 75 weight percent, or about 65 weight percent to about 75 weightpercent diluent, based on the total weight of the build material.

Build materials described herein, in some embodiments, also comprise anon-reactive component that does not comprise a chemical moiety that ispolymerizable with a chemical moiety contained in an oligomeric curablematerial or diluent of the build material. Any non-reactive componentnot inconsistent with the objectives of the present invention may beused. In some embodiments, a non-reactive component comprises one ormore waxes. In some embodiments, suitable waxes comprise hydrocarbonwaxes, including hydrogenated waxes, paraffin waxes, microcrystallinewaxes, fatty ester waxes or mixtures thereof. In some embodiments,suitable waxes comprise one or more urethane waxes.

In some embodiments, a urethane wax of a non-reactive component of abuild material described herein is selected from a class of inert linearurethane waxes having the chemical formula C₁₈H₃₇NRCOOC_(n)H_((2n+1))wherein n is an integer from 4 to 16, and R is H or C1-C20 alkyl. Insome embodiments R is H. In some embodiments, R is C1-C6 alkyl. In someembodiments, R is C1-C10 alkyl. In some embodiments, R is C1-C20 alkyl.Additionally, in some embodiments, urethane waxes of the non-reactivecomponent of a build material comprise ADS038 [1-dodecyl-N-octadecylcarbamate: CH₃(CH₂)₁₇NHCOO(CH₂)₁₁CH₃] and/or ADS043[1-hexadecyl-N-octadecyl carbamate: CH₃(CH₂)₁₇NHCOO(CH₂)₁₅CH₃] waxescommercially available from American Dye Source, Inc. of Baie D'Urfe,Quebec, Canada. In some embodiments, the non-reactive component of abuild material comprises a mixture of C10, C12, C14 and C16 urethanewaxes, where Cn refers to the chain length on the oxygen side of theurethane moiety. In some embodiments, the chain lengths can be variedbased on the desired viscosity and/or stiffness of the uncured buildmaterial; to obtain a cured build material having a desirable stiffness,break elongation, tensile modulus, stability at high temperature, and/ortensile strength; and/or to obtain a build material capable of beingused in specific 3D printing systems to produce finished parts havingdesirable resolution and quality at a desirable speed. In someembodiments, the non-reactive component of a build material comprises amixture of C10, C12, C14 and C16 urethane waxes in a weight ratio ofabout 1 to 1 to 1 to 1. In some embodiments, the weight ratio rangesfrom about 1 to 10 to about 1 to 10 to about 1 to 10 to about 1 to 10.In some embodiments, the weight ratio ranges from about 1 to 20 to about1 to 20 to about 1 to 20 to about 1 to 20. In some embodiments, thenon-reactive component of a build material comprises a mixture of ADS038and ADS043, commercially available from American Dye Source. In someembodiments, the ratio of ADS038 to ADS043 is about 9 to 1. In someembodiments, the ratio of ADS038 to ADS043 is about 8 to 1, about 7 to1, about 6 to 1, about 5 to 1, about 4 to 1, about 3 to 1, or about 2to 1. In some embodiments, the ratio of ADS038 to ADS043 ranges fromabout 9 to 1 to about 2 to 1.

In some embodiments, a non-reactive component of a build materialcomprises a mixture of urethane waxes. In one embodiment, for example, anon-reactive component of a build material comprises a mixture ofdifferent carbon chain length urethane waxes, such as C10, C12, C14 andC16.

In some embodiments, a reactive component as described herein can becombined or mixed in a build material as described herein with anon-reactive component as described herein in any ratio not inconsistentwith the objectives of the present invention. General guidelines forestablishing a suitable ratio of the reactive component to thenon-reactive component can include obtaining a build material having adesirable viscosity and/or stiffness; obtaining a cured build materialhaving a desirable stiffness, break elongation, tensile modulus,stability at high temperature, and/or tensile strength; and/or obtaininga build material capable of being used in 3D printing systems to producefinished parts having desirable resolution and quality at a desirablespeed. In some embodiments, the ratio of a reactive component asdescribed herein to a non-reactive component as described herein isabout 1:1 by weight. In some embodiments, the ratio of a reactivecomponent as described herein to a non-reactive component as describedherein is about 10:1 by weight, 8:1 by weight, 5:1 by weight, 4:1 byweight, 3:1 by weight, or 2:1 by weight. In some embodiments, the ratioof a reactive component as described herein to a non-reactive componentas described herein is about 1:10 by weight, 1:8 by weight, 1:5 byweight, 1:4 by weight, 1:3 by weight, or 1:2 by weight.

However, in some cases, a build material described herein does notcomprise a non-reactive component described hereinabove. In particular,in some embodiments, a build material is free or substantially free of anon-reactive wax such as a hydrocarbon wax, hydrogenated wax, paraffinwax, microcrystalline wax, fatty ester wax, urethane wax, or acombination or mixture thereof. A build material that is free orsubstantially free of a non-reactive wax, in some embodiments, comprisesless than about 5 percent by weight, less than about 1 percent byweight, or less than about 0.5 percent by weight of a hydrocarbon wax,hydrogenated wax, paraffin wax, microcrystalline wax, fatty ester wax,and/or urethane wax described herein, based on the total weight of thebuild material. In some embodiments, a build material that is free orsubstantially free of a non-reactive wax does not comprise any amount ofa hydrocarbon wax, hydrogenated wax, paraffin wax, microcrystalline wax,fatty ester wax, or urethane wax described herein.

A build material described herein, in some embodiments, also comprisesone more additives. In some cases, for example, a build materialdescribed herein further comprises an additive that promotes rapidcuring of the surface of a build material and/or promotes the productionof a tack free finished part. In some embodiments, a build materialdescribed herein further comprises one or more additives selected fromthe group consisting of photoinitiators, inhibitors, stabilizing agents,sensitizers, and combinations thereof. Any additive for these purposesnot inconsistent with the objectives of the present invention may beused.

In some embodiments, an additive that promotes rapid curing of thesurface of a build material and/or promotes the production of a tackfree finished part comprises an amine modified oligomer. A non-limitingexample of an amine modified oligomer useful in some embodimentsdescribed herein is Ebecryl 83, which is an amine modified acrylateoligomer commercially available from Cytec Corp. In some embodiments, anadditional oligomeric species may be present in any amount notinconsistent with the objectives of the present invention. In someembodiments, an additional oligomeric species is present in a buildmaterial as described herein in an amount ranging from about 1 to about5 weight percent. In some embodiments, an additional oligomeric speciesis present in a build material as described herein in an amount lessthan about 3 weight percent.

As a build material described herein comprises one or more curablecompounds, a build material, in some embodiments, further comprises oneor more photoinitiators. Any photoinitiator not inconsistent with theobjectives of the present invention can be used in build materialsdescribed herein. In some embodiments, a suitable photoinitiatorcomprises an alpha-cleavage type (unimolecular decomposition process)photoinitiator or a hydrogen abstraction photosensitizer-tertiary aminesynergist, operable to absorb light preferably between about 250 nm andabout 400 nm or between about 300 nm and about 365 nm, to yield freeradical(s).

Examples of alpha cleavage photoinitiators are Irgacure 184 (CAS947-19-3), Irgacure 369 (CAS 119313-12-1), and Irgacure 819 (CAS162881-26-7). An example of a photosensitizer-amine combination isDarocur BP (CAS 119-61-9) with diethylaminoethylmethacrylate. Thechemical structures of some photoinitiators are provided below:

In some embodiments, suitable photoinitiators comprise benzoins,including benzoin, benzoin ethers, such as benzoin methyl ether, benzoinethyl ether and benzoin isopropyl ether, benzoin phenyl ether andbenzoin acetate, acetophenones, including acetophenone,2,2-dimethoxyacetophenone and 1,1-dichloroacetophenone, benzil, benzilketals, such as benzil dimethyl ketal and benzil diethyl ketal,anthraquinones, including 2-methylanthraquinone, 2-ethylanthraquinone,2-tert-butylanthraquinone, 1-chloroanthraquinone and2-amylanthraquinone, triphenylphosphine, benzoylphosphine oxides, forexample 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Lucirin TPO),benzophenones, such as benzophenone and4,4′-bis(N,N′-dimethylamino)benzophenone, thioxanthones and xanthones,acridine derivatives, phenazine derivatives, quinoxaline derivatives or1-phenyl-1,2-propanedione, 2-O-benzoyl oxime, 1-aminophenyl ketones or1-hydroxyphenyl ketones, such as 1-hydroxycyclohexyl phenyl ketone,phenyl 1-hydroxyisopropyl ketone and 4-isopropylphenyl1-hydroxyisopropyl ketone.

In some embodiments, suitable photoinitiators comprise those operablefor use with a HeCd laser radiation source, including acetophenones,conveniently 2,2-dialkoxybenzophenones and 1-hydroxyphenyl ketones, forexample 1-hydroxycyclohexyl phenyl ketone or 2-hydroxyisopropyl phenylketone (=2-hydroxy-2,2-dimethylacetophenone). Additionally, in someembodiments, suitable photoinitiators comprise those operable for usewith an Ar laser radiation source including benzil ketals, such asbenzil dimethyl ketal. In some embodiments, a photoinitiator comprisesan α-hydroxyphenyl ketone, benzil dimethyl ketal or2,4,6-trimethylbenzoyldiphenylphosphine oxide or a mixture thereof.

Another class of suitable photoinitiators comprises ionic dye-counterion compounds capable of absorbing actinic radiation and generating freeradicals for polymerization initiation. In some embodiments,compositions containing ionic dye-counter ion compounds can be curedmore variably with visible light within the adjustable wavelength rangeof about 400 nm to about 700 nm. Ionic dye-counter ion compounds andtheir mode of operation are disclosed in EP-A-0 223 587 and U.S. Pat.Nos. 4,751,102; 4,772,530 and 4,772,541.

A photoinitiator can be present in a build material in any amount notinconsistent with the objectives of the present invention. In someembodiments, a photoinitiator is present in a build material in anamount of up to about 5 weight percent, based on the total weight of thebuild material. In some embodiments, a photoinitiator is present in abuild material in an amount ranging from about 0.1 weight percent toabout 5 weight percent.

Some embodiments comprise one or more sensitizers. Any sensitizer notinconsistent with the objectives of the present invention may be used.In some embodiments, a sensitizer comprises isopropylthioxanthone (ITX).In some embodiments, a sensitizer comprises 2-chlorothioxanthone (CTX).A sensitizer can be added to a build material to increase theeffectiveness of one or more photoinitiators that may also be present. Asensitizer can be present in a build material in any amount notinconsistent with the objectives of the present invention. In someembodiments, a sensitizer is present in a build material in an amountranging from about 0.1 weight percent to about 2 weight percent, basedon the total weight of the build material. A sensitizer, in someembodiments, is present in a build material in an amount ranging fromabout 0.5 weight percent to about 1 weight percent.

A build material, in some embodiments, further comprises one or morepolymerization inhibitors or stabilizing agents. In some embodiments, apolymerization inhibitor comprises methoxyhydroquinone (MEHQ). Apolymerization inhibitor can be added to a build material to provideadditional thermal stability to the composition. In some embodiments, astabilizing agent comprises one or more anti-oxidants. A stabilizingagent can comprise any anti-oxidant not inconsistent with the objectivesof the present invention. In some embodiments, for example, suitableanti-oxidants include various aryl compounds, including butylatedhydroxytoluene (BHT), which can also be used as a polymerizationinhibitor in some embodiments.

A polymerization inhibitor and/or a stabilizing agent can be present ina build material in any amount not inconsistent with the objectives ofthe present invention. In some embodiments, a polymerization inhibitoris present in a build material in an amount ranging from about 0.1weight percent to about 2 weight percent, based on the total weight ofthe build material. A polymerization inhibitor, in some embodiments, ispresent in a build material in an amount ranging from about 0.5 weightpercent to about 1 weight percent. In some embodiments, a stabilizingagent is present in a build material in an amount ranging from about 0.1weight percent to about 5 weight percent or from about 0.5 weightpercent to about 4 weight percent. In some embodiments, a stabilizingagent is present in a build material in an amount ranging from about 1weight percent to about 3 weight percent.

Build materials described herein can comprise any combination ofcomponents described herein not inconsistent with the objectives of thepresent invention. For example, any oligomeric curable materialdescribed herein can be combined with any reactive component describedherein, any diluent(s) described herein, and/or any non-reactivecomponent described herein in any amounts not inconsistent with theobjectives of the present invention. The chemical identities and/oramounts of the components of a build material described herein can beselected based on one or more of the desired viscosity of the buildmaterial, the desired break elongation of the cured build material, thedesired tensile modulus of the cured build material, the desired tensilestrength of the cured build material, and the desired resistance todistortion of the cured build material. In some embodiments, forinstance, a build material having a high tensile modulus and/or a hightensile strength comprises 10-40 weight percent urethane (meth)acrylateoligomer; 30-80 weight percent (meth)acrylic diluent; 3-15 weightpercent isocyanurate (meth)acrylate; and 0-5 weight percent non-reactivewax component. In other embodiments, a high-stiffness build materialcomprises 15-30 weight percent urethane (meth)acrylate oligomer; 50-80weight percent (meth)acrylic diluent; 3-15 weight percent non-oligomericurethane (meth)acrylate, urea (meth)acrylate, or isocyanurate(meth)acrylate; and 0-3 weight percent non-reactive wax component.

In addition, build materials described herein can have any suitablefreezing and melting points not inconsistent with the objectives of thepresent invention. In some embodiments, a build material has freezingand melting points consistent with temperatures used in some 3D printingsystems. In some embodiments, the freezing point of a build material isgreater than about 40° C. In some embodiments, for example, a buildmaterial has a freezing point centered at a temperature ranging fromabout 45° C. to about 55° C. In some embodiments, a build material has amelting point centered at a temperature ranging from about 50° C. toabout 80° C. A build material, in some embodiments, has a melting pointranging from about 50° C. to about 65° C. In some embodiments, thefreezing point of a build material is lower than about 40° C. or lowerthan about 25° C.

In some embodiments, a build material has a viscosity consistent withthe requirements and parameters of one or more 3D printing systems. Insome embodiments, a build material described herein has a viscosityranging from about 8.0 cP to about 18.0 cP at a temperature of about 65°C. In some embodiments, a build material has a viscosity ranging fromabout 8.0 cP to about 14.0 cP, about 9.5 cP to about 12.5 cP, or about10.5 cP to about 12.5 cP at a temperature of about 65° C.

In some embodiments, a build material described herein has a viscosityranging from about 8.0 cP to about 19.0 cP at a temperature of about 80°C. In some embodiments, a build material described herein has aviscosity ranging from about 8.0 cP to about 13.5 cP, about 11.0 cP toabout 14.0 cP, about 11.5 cP to about 13.5 cP, or from about 12.0 cP toabout 13.0 cP at a temperature of about 80° C.

In some embodiments, a build material in the non-cured state has one ormore of the following properties:

1. Melting point from about 45° C. to about 65° C. (MP must be less thanthe jetting temperature);

2. Freezing point from about 33° C. to about 60° C.;

3. jetting viscosity of about 8 to about 18 cP at 70-95° C.; and

4. Thermally stable for at least 3 days at the jetting temperature.

In some embodiments, a build material in the non-cured state has one ormore of the following properties:

1. Melting point lower than about 25° C. (the melting point must in someembodiments be less than the jetting temperature but need not be at orabove room temperature);

2. Freezing point lower than about 25° C.;

3. Jetting viscosity of about 8 to about 19 cP at 70-95° C.; and

4. Thermally stable for at least 3 days at the jetting temperature.

Moreover, when in the cured state, a build material described herein, insome embodiments, can have one or more of the following properties:

1. Tensile strength of at least about 35 MPa, at least about 50 MPa, orat least about 60 MPa (as measured by ASTM D 638);

2. Tensile modulus of at least about 1380 MPa, at least about 2250 MPa,or at least about 2400 MPa (as measured by ASTM D 638);

3. Break elongation of at least about 10% (as measured by ASTM D 638);

4. Hardness of at least 60 shore D (as measured by ASTM D 2240);

5. Impact strength of at least 0.2 ft-1b/in (10.7 N-cm/cm) (Izodnotched, as measured by ASTM D 256);

6. Flexural strength of at least 10 MPa (as measured by ASTM D 638); and

7. Flexural modulus of at least 17 MPa (as measured by ASTM D 792).

In some embodiments, a build material when cured exhibits a tensilemodulus of about 1380-3150 MPa when measured according to ASTM D 638. Insome embodiments, a build material when cured exhibits a tensile modulusof about 1500-3150 MPa, about 1500-2200 MPa, about 1500-1900 MPa, about1550-1850 MPa, about 1750-1850 MPa, about 1700-1800 MPa, about 2000-3150MPa, about 2000-3000 MPa, about 2200-3150 MPa, about 2200-3000 MPa,about 2250-3150 MPa, about 2250-3000 MPa, about 2250-2800 MPa, about2300-3150 MPa, about 2300-3000 MPa, about 2300-2800 MPa, about 2400-3150MPa, about 2400-3000 MPa, or about 2400-2800 MPa when measured accordingto ASTM D 638. In some embodiments, a build material when cured exhibitsa tensile modulus greater than about 2200 MPa or greater than about 2400MPa when measured according to ASTM D 638.

In some embodiments, a build material when cured exhibits a breakelongation of about 5-24% when measured according to ASTM D 638. In someembodiments, a build material when cured exhibits a break elongation ofabout 5-20%, about 10-20%, about 10-18%, about 10-15%, about 12-22%,about 12-18%, or about 14-20% when measured according to ASTM D 638.

In some embodiments, a build material when cured exhibits a tensilestrength of about 24-76 MPa, about 35-76 MPa, about 35-42 MPa, about36-40 MPa, about 38-40 MPa, about 44-76 MPa, about 44-70 MPa, about44-65 MPa, about 46-76 MPa, about 46-70 MPa, about 46-65 MPa, about50-76 MPa, about 50-70 MPa, about 50-65 MPa, about 55-76 MPa, about55-70 MPa, or about 55-65 MPa when measured according to ASTM D 638. Insome embodiments, a build material when cured exhibits a tensilestrength greater than about 42 MPa, greater than about 46 MPa, greaterthan about 50 MPa, greater than about 55 MPa, greater than about 60 MPa,or greater than about 65 MPa when measured according to ASTM D 638.

In some embodiments, a build material when cured exhibits both a tensilemodulus as described herein and a break elongation as described herein.Any combination of properties described herein not inconsistent with theobjectives of the present invention may be used. Further, the value ofone or more mechanical properties described herein, in some instances,can be selected based on one or more of the chemical identity and amountof the oligomeric curable material, the chemical identity and amount ofthe diluent, the chemical identity and amount of the reactive component,and the chemical identity and amount of the non-reactive component. Forexample, in some embodiments, a build material comprising about 10 to 30percent by weight of an oligomeric curable material; about 50 to 75percent by weight of at least one diluent; about 3 to 15 percent byweight of a reactive component; and less than about 5 percent by weightof a non-reactive wax can, when cured, exhibit a tensile modulus ofabout 2300-3150 MPa and a break elongation of about 5-20% when measuredaccording to ASTM D 638. In some embodiments, a build material whencured exhibits a tensile modulus of about 1500-2200 MPa and a breakelongation of about 10-24% when measured according to ASTM D 638. Insome embodiments, a build material when cured exhibits a tensile modulusof about 1500-1900 MPa and a break elongation of about 12-22% whenmeasured according to ASTM D 638. In some embodiments, a build materialwhen cured exhibits a tensile modulus of about 1550-1850 MPa and a breakelongation of about 14-20% when measured according to ASTM D 638. Insome embodiments, a build material when cured exhibits a tensile modulusof about 1750-1850 MPa and a break elongation of about 14-20% whenmeasured according to ASTM D 638. In some embodiments, a build materialwhen cured exhibits a tensile modulus of about 1700-1800 MPa and a breakelongation of about 12-22% when measured according to ASTM D 638. Insome embodiments, a build material when cured exhibits a tensile modulusof about 2250-3150 MPa and a break elongation of about 5-20% whenmeasured according to ASTM D 638. In some embodiments, a build materialwhen cured exhibits a tensile modulus of about 2400-3000 MPa and a breakelongation of about 10-20% when measured according to ASTM D 638.

In some embodiments, a build material when cured exhibits a tensilemodulus described herein, a break elongation described herein, and atensile strength described herein. Any combination of propertiesdescribed herein not inconsistent with the objectives of the presentinvention may be used. Further, the value of one or more mechanicalproperties described herein, in some instances, can be selected based onone or more of the chemical identity and amount of the oligomericcurable material, the chemical identity and amount of the diluent, thechemical identity and amount of the reactive component, and the chemicalidentity and amount of the non-reactive component. For example, in someembodiments, a build material comprising about 10 to 30 percent byweight of an oligomeric curable material; about 50 to 75 percent byweight of at least one diluent; about 3 to 15 percent by weight of areactive component; and less than about 5 percent by weight of anon-reactive wax can, when cured, exhibit a tensile modulus of about2300-3150 MPa, a tensile strength of about 46-75 MPa, and a breakelongation of about 5-20% when measured according to ASTM D 638.

In addition, build materials described herein can exhibit desirableproperties at elevated temperatures. In some embodiments, a buildmaterial when cured is capable of exhibiting a heat deflectiontemperature (HDT) ranging from about 45° C. to about 100° C. when testedaccording to ASTM D 648. In some embodiments, a build material whencured is capable of exhibiting an HDT ranging from about 45° C. to about90° C., about 45° C. to about 80° C., about 60° C. to about 100° C.,about 60° C. to about 80° C., about 70° C. to about 100° C., about 70°C. to about 90° C., or about 70° C. to about 80° C. when testedaccording to ASTM D 648.

In some embodiments, a build material as described herein is produced byplacing all components of the build material in a reaction vessel andheating the resulting mixture to a temperature ranging from about 75° C.to about 85° C. with stirring. The heating and stirring are continueduntil the mixture attains a substantially homogenized molten state. Themolten mixture is filtered while in a flowable state to remove any largeundesirable particles that may interfere with jetting. The filteredmixture is then cooled to ambient temperatures until it is heated in theink jet printer.

In another aspect, compositions comprising three dimensionally printedarticles or objects are described herein. A three dimensionally printedarticle or object can comprise any embodiment of a build materialdescribed herein. In some embodiments, a composition comprises a threedimensionally printed article comprising a build material, the buildmaterial comprising an oligomeric curable material, a reactive componentthat is solid at 25° C., and at least one diluent, wherein the reactivecomponent comprises at least one chemical moiety that is polymerizablewith a chemical moiety contained in the oligomeric curable materialand/or the at least one diluent. In some embodiments, the build materialof a composition described herein further comprises a non-reactivecomponent that does not comprise a chemical moiety that is polymerizablewith a chemical moiety contained in the oligomeric curable material orthe at least one diluent.

In other embodiments, a composition comprises a three dimensionallyprinted article comprising a build material, the build materialcomprising about 10 to 30 percent by weight of an oligomeric curablematerial; about 50 to 75 percent by weight of at least one diluent;about 3 to 15 percent by weight of an isocyanurate (meth)acrylate; andless than about 5 percent by weight of a non-reactive wax component.Further, in some cases, the build material when cured exhibits a tensilemodulus greater than about 2200 MPa when measured according to ASTM D638.

In some embodiments, a composition comprises a three dimensionallyprinted article comprising a build material as described herein andfurther comprising a support material. A support material can be used tosupport at least one layer of a build material during the 3D printingprocess. In some embodiments, a three dimensionally printed articledescribed herein comprises a plurality of layers of the build material,wherein the layers of the build material are deposited according to datain a computer readable format. In some embodiments, at least one of thedeposited layers of build material is supported by a support material.In some embodiments, the support material is removable to completeproduction of the three dimensionally printed article or object.

In another aspect, methods of printing a three dimensional article orobject are described herein. Embodiments of methods of printing a threedimensional article can comprise any embodiment of a build materialdescribed herein. In some embodiments, the layers of the build materialare deposited according to an image of the three dimensional article ina computer readable format. In some embodiments, the build material isdeposited according to preselected computer aided design (CAD)parameters.

In some embodiments, a method of printing a three dimensional articlefurther comprises supporting at least one of the layers of the buildmaterial with a support material. In some embodiments, a method ofprinting a three dimensional article further comprises curing the buildmaterial. In some embodiments, a method of printing a three dimensionalarticle further comprises subjecting the build material toelectromagnetic radiation of sufficient wavelength and intensity to curethe build material. In some embodiments of printing a three dimensionalarticle, a layer of deposited build material is cured prior to thedeposition of another or adjacent layer of build material.

In some embodiments, a preselected amount of build material describedherein is heated to the appropriate temperature and jetted through theprint head or a plurality of print heads of a suitable inkjet printer toform a layer on a build support platform in a build chamber. In someembodiments, each layer of build material is deposited according to thepreselected CAD parameters. A suitable print head to deposit the buildmaterial, in some embodiments, is the piezoelectric Z850 print headavailable from Xerox Corporation's Office Products Business Unit inWilsonville, Oreg. Additional suitable print heads for the deposition ofbuild and support materials described herein are commercially availablefrom a variety of ink jet printing apparatus manufacturers. For example,the Taipan print head available from Xerox or Ricoh print heads may alsobe used in some embodiments.

In some embodiments comprising a method of printing a three dimensionalarticle comprising a build material as described herein, the buildmaterial solidifies upon deposition. In some embodiments, the buildmaterial remains substantially fluid upon deposition. In someembodiments, the temperature of the build environment can be controlledso that the jetted droplets of build material solidify on contact withthe receiving surface. In other embodiments, the jetted droplets ofbuild material do not solidify on contact with the receiving surface,remaining in a substantially fluid state. In some embodiments, aftereach layer is deposited, the deposited material is planarized and curedwith electromagnetic (e.g., UV) radiation prior to the deposition of thenext layer. Optionally, several layers can be deposited beforeplanarization and curing, or multiple layers can be deposited and curedfollowed by one or more layers being deposited and then planarizedwithout curing. Planarization corrects the thickness of one or morelayers prior to curing the material by evening the dispensed material toremove excess material and create a uniformly smooth exposed or flatup-facing surface on the support platform of the printer. In someembodiments, planarization is accomplished with a wiper device, such asa roller, which may be counter-rotating in one or more printingdirections but not counter-rotating in one or more other printingdirections. In some embodiments, the wiper device comprises a roller anda wiper that removes excess material from the roller. In someembodiments, the wiper device is heated. The process is continued untila useful finished three dimensional design is prepared. It should benoted that the consistency of the jetted build material of the presentinvention prior to curing must be sufficient to retain its shape and notbe subject to excessive viscous drag from the planarizer.

Moreover, a support material, in some embodiments, can be deposited in amanner consistent with that described herein for the build material. Thesupport material, for example, can be deposited according to thepreselected CAD parameters such that the support material is adjacent orcontinuous with one or more layers of the build material. Jetteddroplets of the support material, in some embodiments, solidify orfreeze on contact with the receiving surface. In some embodiments, thedeposited support material is also subjected to planarization.

Layered deposition of the build material and support material can berepeated until the three dimensional article has been formed. In someembodiments, a method of printing a three dimensional article furthercomprises removing the support material from the build material. Thesupport material can be removed by any means known to one of ordinaryskill in the art and not inconsistent with the objectives of the presentinvention.

Embodiments described herein are further illustrated in the followingnon-limiting examples.

Example 1 Build Material

A build material consistent with embodiments described herein wasprovided in accordance with the formulation of Table I.

TABLE I Build Material Component Amount (Wt. %) Oligomeric CurableMaterial¹ 20.47 Reactive Component² 5.90 Diluent(s)³ 61.43 Non-ReactiveComponent⁴ 5.96 Additive for Curing/Tackiness⁵ 1.83 Photoinitiator⁶ 4.29Sensitizer⁷ 0.10 Inhibitor⁸ 0.02 Total 100 ¹BR-741 - Bomar SpecialtiesCo., Winsted, CT. ²Tris(2-hydroxy ethyl)isocyanurate triacrylate - SR368 - SARTOMER Company, Exton, PA. ³Mixture of IBOA (40.54%), SR 423A(8.54%), and SR 205 (12.35%) - SARTOMER Company, Exton, PA. ⁴Mixture ofC10, C12, C14, and C16 urethane waxes - Hampford Research, Inc.,Stratford, CT. ⁵Amine modified oligomer - Ebecryl 83 - Cytec IndustriesInc., Willow Island, WV. ⁶Mixture of Irgacure 184 (3.94%) and Irgacure819 (0.35%) - Ciba Specialty Chemicals, Inc. (BASF), Basel, Switzerland.⁷ITX - Cytec Industries Inc., Willow Island, WV. ⁸BHT - Chemtura Corp.Middlebury, CT.

The oligomeric curable material (20.47 grams), reactive component (5.90grams), diluents (61.43 grams), non-reactive component (5.96 grams),additive for curing/tackiness (1.83 grams), photoinitiator (4.29 grams),sensitizer (0.10 grams), and inhibitor (0.02 grams) were charged into avessel equipped with mechanical stirring and a heating unit. The mixturewas then heated to about 80° C.-90° C. After the mixture was melted,stirring was begun, and the mixture was blended for about 1-2 hours at80° C.-90° C. The liquid was then filtered with a 1 micron filter toremove solid particles. The build material provided in Table I had aviscosity of 12.0 centipoise at a temperature of 65° C.

The resulting build material was jetted at about 65° C.-68° C. through aProjet 3000 System from 3D Systems using a Xerox Z 850 print head toform three dimensional parts. The cured build material exhibited atensile modulus of 1701 MPa when tested according to ASTM D 638, a breakelongation of 19.9% when tested according to ASTM D 638, and a tensilestrength of 38.8 MPa when tested according to ASTM D 638. Further, thecured build exhibited a heat deflection temperature (HDT) higher thanabout 70° C. when tested according to ASTM D 648.

Example 2 Build Material

A build material consistent with embodiments described herein wasprovided in accordance with the formulation of Table II.

TABLE II Build Material Component Amount (Wt. %) Oligomeric CurableMaterial⁹ 14.15 Reactive Component¹⁰ 8.65 Diluent(s)¹¹ 74.05Photoinitiator¹² 3.09 Inhibitor¹³ 0.07 Total 100 ⁹BR-571 - BomarSpecialties Co., Winsted, CT. ¹⁰Tris(2-hydroxy ethyl)isocyanuratetriacrylate - SR 368 - SARTOMER Company, Exton, PA. ¹¹Mixture of SR 506(39.97%), SR 833 (7.28%), and SR 205 (26.80%) - SARTOMER Company, Exton,PA. ¹²Mixture of Irgacure 184 (2.06%) and Irgacure 819 (1.03%) - CibaSpecialty Chemicals, Inc. (BASF), Basel, Switzerland. ¹³BHT - ChemturaCorp. Middlebury, CT.

The oligomeric curable material (14.15 grams), reactive component (8.65grams), diluents (74.05 grams), photoinitiator (3.09 grams), andinhibitor (0.07 grams) were charged into a vessel equipped withmechanical stirring and a heating unit. The mixture was then heated toabout 80° C.-90° C. After the mixture was melted, stirring was begun,and the mixture was blended for about 1-2 hours at 80° C.-90° C. Theliquid was then filtered with a 1 micron filter to remove solidparticles.

The resulting build material was jetted at about 65° C.-68° C. through aProjet 3000 System from 3D Systems using a Xerox Z 850 print head toform three dimensional parts. The cured build material exhibited atensile modulus of 2455 MPa when tested according to ASTM D 638, a breakelongation of 10.28% when tested according to ASTM D 638, and a tensilestrength of 60.63 MPa when tested according to ASTM D 638.

Example 3 Build Material

A build material consistent with embodiments described herein wasprovided in accordance with the formulation of Table Ill.

TABLE III Build Material Component Amount (Wt. %) Oligomeric CurableMaterial¹⁴ 20.36 Reactive Component¹⁵ 10.18 Diluent(s)¹⁶ 65.13Photoinitiator¹⁷ 4.28 Inhibitor¹⁸ 0.07 Total 100 ¹⁴3:1 mixture of BR-741and BR-571 - Bomar Specialties Co., Winsted, CT. ¹⁵Tris(2-hydroxyethyl)isocyanurate triacrylate - SR 368 - SARTOMER Company, Exton, PA.¹⁶Mixture of SR 423A (28.50%), SR 833 (9.16%), SR 340 (20.35%), andGENOMER 1122 (7.12%) - SARTOMER Company, Exton, PA, and RAHN AG, Zurich,Switzerland. ¹⁷Mixture of Irgacure 184 (2.75%) and Irgacure 819(1.53%) - Ciba Specialty Chemicals, Inc. (BASF), Basel, Switzerland.¹⁸BHT - Chemtura Corp. Middlebury, CT.

The oligomeric curable material (20.36 grams), reactive component (10.18grams), diluents (65.13 grams), photoinitiator (4.28 grams), andinhibitor (0.07 grams) were charged into a vessel equipped withmechanical stirring and a heating unit. The mixture was then heated toabout 80° C.-90° C. After the mixture was melted, stirring was begun,and the mixture was blended for about 1-2 hours at 80° C.-90° C. Theliquid was then filtered with a 1 micron filter to remove solidparticles.

The resulting build material was jetted at about 65° C.-68° C. through aProjet 3000 System from 3D Systems using a Xerox Z 850 print head toform three dimensional parts. The cured build material exhibited atensile modulus of 2427 MPa when tested according to ASTM D 638, a breakelongation of 16.04% when tested according to ASTM D 638, and a tensilestrength of 53.13 MPa when tested according to ASTM D 638.

Example 4 Build Material

A build material consistent with embodiments described herein wasprovided in accordance with the formulation of Table IV.

TABLE IV Build Material Component Amount (Wt. %) Oligomeric CurableMaterial¹⁹ 21.28 Reactive Component²⁰ 5.32 Diluent(s)²¹ 69.16Photoinitiator²² 4.17 Inhibitor²³ 0.07 Total 100 ¹⁹3:1 mixture of BR-741and BR-571 - Bomar Specialties Co., Winsted, CT. ²⁰Tris(2-hydroxyethyl)isocyanurate triacrylate - SR 368 - SARTOMER Company, Exton, PA.²¹Mixture of SR 423A (37.24%), SR 833 (5.32%), SR 205 (15.96%), andGENOMER 1122 (10.64%) - SARTOMER Company, Exton, PA, and RAHN AG,Zurich, Switzerland. ²²Mixture of Irgacure 184 (3.21%) and Irgacure 819(0.96%) - Ciba Specialty Chemicals, Inc. (BASF), Basel, Switzerland.²³BHT - Chemtura Corp. Middlebury, CT.

The oligomeric curable material (21.28 grams), reactive component (5.32grams), diluents (69.16 grams), photoinitiator (4.17 grams), andinhibitor (0.07 grams) were charged into a vessel equipped withmechanical stirring and a heating unit. The mixture was then heated toabout 80° C.-90° C. After the mixture was melted, stirring was begun,and the mixture was blended for about 1-2 hours at 80° C.-90° C. Theliquid was then filtered with a 1 micron filter to remove solidparticles.

The resulting build material was jetted at about 65° C.-68° C. through aProjet 3000 System from 3D Systems using a Xerox Z 850 print head toform three dimensional parts. The cured build material exhibited atensile modulus of 2523 MPa when tested according to ASTM D 638, a breakelongation of 11.51% when tested according to ASTM D 638, and a tensilestrength of 63.11 MPa when tested according to ASTM D 638.

Example 5 Build Material

A build material consistent with embodiments described herein wasprovided in accordance with the formulation of Table V.

TABLE V Build Material Component Amount (Wt. %) Oligomeric CurableMaterial²⁴ 16.84 Reactive Component²⁵ 6.81 Diluent(s)²⁶ 72.03Photoinitiator²⁷ 4.23 Inhibitor²⁸ 0.10 Total 100 ²⁴BR-571 - BomarSpecialties Co., Winsted, CT. ²⁵Tris(2-hydroxy ethyl)isocyanuratetriacrylate - SR 368 - SARTOMER Company, Exton, PA. ²⁶Mixture of SR 506(16.84%), SR 833 (5.51%), SR 272 (24.16%), and SR 205 (25.52%) -SARTOMER Company, Exton, PA. ²⁷Mixture of Irgacure 184 (3.06%) andIrgacure 819 (1.17%) - Ciba Specialty Chemicals, Inc. (BASF), Basel,Switzerland. ²⁸BHT - Chemtura Corp. Middlebury, CT.

The oligomeric curable material (16.84 grams), reactive component (6.81grams), diluents (72.03 grams), photoinitiator (4.23 grams), andinhibitor (0.10 grams) were charged into a vessel equipped withmechanical stirring and a heating unit. The mixture was then heated toabout 80° C.-90° C. After the mixture was melted, stirring was begun,and the mixture was blended for about 1-2 hours at 80° C.-90° C. Theliquid was then filtered with a 1 micron filter to remove solidparticles.

The resulting build material was jetted at about 65° C.-68° C. through aProjet 3000 System from 3D Systems using a Xerox Z 850 print head toform three dimensional parts. The cured build material exhibited atensile modulus of 1862 MPa when tested according to ASTM D 638, a breakelongation of 6.41% when tested according to ASTM D 638, and a tensilestrength of 43.42 MPa when tested according to ASTM D 638.

Example 6 Build Material

A build material consistent with embodiments described herein wasprovided in accordance with the formulation of Table VI.

TABLE VI Build Material Component Amount (Wt. %) Oligomeric CurableMaterial²⁹ 16.11 Reactive Component³⁰ 11.76 Diluent(s)³¹ 68.26Photoinitiator³² 3.80 Inhibitor³³ 0.08 Total 100 ²⁹BR-741 - BomarSpecialties Co., Winsted, CT. ³⁰Tris(2-hydroxy ethyl)isocyanuratetriacrylate - SR 368 - SARTOMER Company, Exton, PA. ³¹Mixture of SR 205(40.48%), SR 833 (8.28%), and SR 506 (19.50%) - SARTOMER Company, Exton,PA. ³²Mixture of Irgacure 184 (2.34%) and Irgacure 819 (1.46%) - CibaSpecialty Chemicals, Inc. (BASF), Basel, Switzerland. ³³BHT - ChemturaCorp. Middlebury, CT.

The oligomeric curable material (16.11 grams), reactive component (11.76grams), diluents (68.26 grams), photoinitiator (3.80 grams), andinhibitor (0.08 grams) were charged into a vessel equipped withmechanical stirring and a heating unit. The mixture was then heated toabout 80° C.-90° C. After the mixture was melted, stirring was begun,and the mixture was blended for about 1-2 hours at 80° C.-90° C. Theliquid was then filtered with a 1 micron filter to remove solidparticles.

The resulting build material was jetted at about 65° C.-68° C. through aProjet 3000 System from 3D Systems using a Xerox Z 850 print head toform three dimensional parts. The cured build material exhibited atensile modulus of 2779 MPa when tested according to ASTM D 638, a breakelongation of 7.09% when tested according to ASTM D 638, and a tensilestrength of 67.8 MPa when tested according to ASTM D 638.

All patent documents referred to herein are incorporated by reference intheir entireties. Various embodiments of the invention have beendescribed in fulfillment of the various objectives of the invention. Itshould be recognized that these embodiments are merely illustrative ofthe principles of the present invention. Numerous modifications andadaptations thereof will be readily apparent to those skilled in the artwithout departing from the spirit and scope of the invention.

That which is claimed:
 1. A build material for use in athree-dimensional printing system comprising: about 10 to 30 percent byweight of an oligomeric curable material; about 50 to 75 percent byweight of at least one diluent; about 3 to 15 percent by weight of anisocyanurate (meth)acrylate; and less than about 5 percent by weight ofa non-reactive wax component.
 2. The build material of claim 1, whereinthe build material further comprises one or more additives selected fromthe group consisting of photoinitiators, inhibitors, stabilizing agents,sensitizers, and combinations thereof.
 3. The build material of claim 1,wherein the oligomeric curable material contains one or more(meth)acrylate moieties.
 4. The build material of claim 1, wherein theoligomeric curable material is a urethane (meth)acrylate having aviscosity ranging from about 10,000 cps to about 300,000 cps.
 5. Thebuild material of claim 1, wherein the oligomeric curable materialcomprises about 15 to 25 percent by weight of the build material.
 6. Thebuild material of claim 1, wherein the at least one diluent contains oneor more (meth)acrylate moieties.
 7. The build material of claim 1,wherein the isocyanurate (meth)acrylate is an isocyanuratetri(meth)acrylate.
 8. The build material of claim 1, wherein theisocyanurate (meth)acrylate is tris(2-hydroxy ethyl)isocyanuratetriacrylate.
 9. The build material of claim 1, wherein the isocyanurate(meth)acrylate comprises about 5 to about 15 percent by weight of thebuild material.
 10. The build material of claim 1, wherein the buildmaterial comprises less than about 1 percent by weight of a non-reactivewax component.
 11. The build material of claim 1, wherein the buildmaterial when cured exhibits a tensile modulus of about 2250-3150 MPawhen measured according to ASTM D
 638. 12. The build material of claim1, wherein the build material when cured exhibits a tensile strength ofabout 46-76 MPa when measured according to ASTM D
 638. 13. The buildmaterial of claim 1, wherein the build material when cured exhibits abreak elongation of about 5-20% when measured according to ASTM D 638.14. The build material of claim 1, wherein the build material when curedexhibits a heat deflection temperature ranging from about 45° C. toabout 100° C. when tested according to ASTM D
 648. 15. The buildmaterial of claim 1, wherein the build material has a viscosity rangingfrom about 8.0 centipoise to about 18.0 centipoise at a temperature ofabout 65° C.
 16. A composition comprising: a three-dimensionally printedarticle comprising the build material of claim
 1. 17. A method ofprinting a three dimensional article comprising: selectively depositinglayers of a fluid build material to form the three dimensional articleon a substrate, the build material comprising the build material ofclaim
 1. 18. The method of claim 17, wherein the layers of the buildmaterial are deposited according to an image of the three dimensionalarticle in a computer readable format.
 19. The method of claim 17further comprising supporting at least one of the layers of the buildmaterial with a support material.
 20. The method of claim 17 furthercomprising curing the build material.